What is Ohms Law?
Current (I) flowing through a conductor is directly proportional to the potential difference (V) across the ends of the conductor. A German scientist named Georg Ohm performed many experiments in an effort to show the correlation between current and potential difference and this law became Ohms law on his name.
Mathematical Representation of Ohms Law
VαI or
V= RI or
V/I=R=a constant
Where R is known as resistance of the conductor.
Deduction of Ohm’s Law
Drift velocity is given by Vd=eEt/m where Vd is the drift velocity
But Electric field across the conductor of length l is i.e. E=V/l
Thus Vd=(eV/ml)t
Also, I=Anevd
By putting value of vd in the equation of I
I=Ane(eV/ml)t=(Ante^2/ml)V
Or V/I=ml/Ante^2=R Where R is a constant for a given conductor. It is known as the resistance of the conductor.
Thus V=RI
Check the following video for a very nice explanation
